Green Technology Practice Questions

Correct answer: Concentrated Solar Power

Concentrated Solar Power (CSP) systems use mirrors to focus sunlight, which heats a fluid to produce steam that drives a turbine. This differs from PV cells, which convert sunlight directly into electricity using semiconductors.

Correct answer: Leadership in Energy and Environmental Design

LEED is a widely used green building rating system developed by the U.S. Green Building Council. It provides a framework for healthy, highly efficient, and cost-saving green buildings.

Correct answer: Water Vapor

Hydrogen fuel cells combine hydrogen and oxygen to produce electricity through an electrochemical reaction. The only physical byproducts of this process are heat and pure water (H2O).

Correct answer: Second Generation

Second-generation biofuels are produced from lignocellulosic biomass or woody crops, meaning they do not compete directly with food crops for land. First-generation biofuels are made directly from food sources like sugar and vegetable oil.

Correct answer: Underground geological formations

CCS technology captures carbon dioxide emissions at their source before they reach the atmosphere. The captured CO2 is then compressed and transported to be stored permanently in underground geological formations such as deep saline aquifers or depleted oil and gas reservoirs.

Correct answer: Green Hydrogen

Green hydrogen is the cleanest form of hydrogen production because the electricity used for electrolysis comes from renewables. Blue hydrogen is made from natural gas with carbon capture, while grey hydrogen is made without carbon capture.

Correct answer: Decomposing organic waste without oxygen

Anaerobic digestion uses microorganisms to decompose biodegradable waste in the absence of oxygen. The resulting biogas, made mostly of methane, can be used for heating or electricity generation.

Correct answer: Produces as much energy as it uses

Net Zero Energy (NZE) buildings are highly energy-efficient structures that generate their own power on-site using renewables. The total energy the building consumes is roughly equal to the amount of renewable energy it produces.

Correct answer: Two-way flow between utility and customer

Smart Grids use digital technology to monitor and manage the transport of electricity. This two-way flow of electricity and information between utilities and customers allows for better integration of renewables and more efficient energy distribution.

Correct answer: Generator

The wind turns the blades, which spin a shaft connected to a generator. Inside the generator, magnets and copper coils work together to produce electricity through electromagnetic induction.

Correct answer: Transferring ground heat for heating and cooling

Geothermal heat pumps take advantage of the constant temperature of the earth just below the surface. They circulate fluid through underground pipes to transfer heat into a building in winter and out in summer.

Correct answer: Ocean surface water and deep cold water

OTEC uses the warm surface water of the ocean to vaporize a fluid with a low boiling point, which turns a turbine. Deep cold water is then used to condense the vapor back into a liquid to repeat the cycle.

Correct answer: Phytoremediation

Phytoremediation is a cost-effective, plant-based approach where vegetation is used to absorb, sequester, or degrade environmental contaminants. It is often used to treat heavy metals or hydrocarbons in brownfield sites.

Correct answer: EVs selling stored energy back to the grid during peak demand

V2G technology allows EV batteries to store energy and discharge it back into the electrical grid when needed. This helps balance the grid and provides a way for EV owners to earn incentives or lower their energy costs.

Correct answer: Cobalt

Cobalt is highly valued for its ability to provide high energy density and thermal stability in battery cathodes. However, due to ethical and cost concerns, researchers are actively looking for ways to reduce or eliminate cobalt in future battery designs.

Correct answer: Optimizing crop yields while reducing resource waste

Precision agriculture uses GPS, IoT sensors, and satellite imagery to observe and respond to variability within fields. This ensures crops receive exactly what they need for optimum health and productivity, reducing water and fertilizer waste and environmental runoff.

Correct answer: Underwater wind turbines

Tidal stream generators use the kinetic energy of moving water to power turbines, much like wind turbines use moving air. Because water is much denser than air, these turbines can generate significant power even at low speeds.

Correct answer: Rare earth elements and precious metals

Electronics contain valuable materials like gold, silver, copper, and palladium, as well as rare earth elements. Recycling prevents these toxic materials from leaching into the soil while reducing the need for destructive mining.

Correct answer: The share of radiation reflected by a surface

Albedo refers to the reflectivity of a surface, i.e. the share of incoming radiation it reflects. Dark urban surfaces like asphalt have low albedo and absorb heat, contributing to the Urban Heat Island effect; green roofs increase reflectivity and provide cooling through evapotranspiration.

Correct answer: Light Emitting Diodes (LEDs)

LEDs are highly energy-efficient because they emit very little heat and convert most of their energy into light. They last significantly longer than incandescent or CFL bulbs, reducing both energy use and waste.